Cuddihy's Cut

Cuddihy's Cut on the events of the day....

Thursday, June 15, 2006

Signing off

As is probably obvious from perusing the date of posts, I haven't posted much lately. My wife is pregnant with our first and I'm at full throttle for the next few months trying to finish my Master's thesis, so I don't imagine I'll find much time to post much in the future either.In all, I'm not sure I have all that much to say that others in the blogosphere don't say better and faster than me. I take exception to some things that Rand Simberg and Keith Cowing say because I think they're often unfair or extremely biased against government efforts. But on the whole I have them to pick on because both of them are so prolific with content. (which I'm not) I do have an original perspective on some topics due to my position, but generally the things I would like to post--such as studies i've done, and some documents by others that I think bring an interesting perspective or introduce hard scientific facts where alt.space fancies run wild. But most of this content consists of files that can't be uploaded for free to services like Blogger. Since I don't right now have the time to run my own domain, I'm going to stop posting until I can back my opinions with content. In the meantime, check out Space Cynic for much needed doses of sanity in the alt.space or New Space world.

Monday, May 15, 2006

Comments are hosed again

Fake but accurate? and, LH2 vs RP-1.

NASAWatch posted the official cancellation of the reusable RS-25 for the CaLV. Presumably, this means that NASA is indeed going to the RS-68 with a 10 m rocket body, as originally reported in a now retracted article.

It seems like the RS-68 is indeed the new choice for the 'SDLV', which, as others have now pointed out, has very little left that is 'shuttle derived.'

In fact, as Chairforce Engineer has stated, the SDLV now bears more in common with the Saturn V rocket than the Shuttle. All that's left, in my opinion, is to shift from the absurdity of a LH2 powered first stage to a Kerosene (RP-1) first stage. Then, at last, we would be back to where we started. Von Braun proven right again.

Lately it's become pretty clear to me that using LH2 for a lower stage is pretty much a fool's errand. I recently had to run some launch numbers for class (capstone) project that required launching multiple heavy satellites to a high LEO orbit (500 km and 1000 km). The only two launchers I was allowed to consider were the Atlas V and Delta IV. Imagine my shock when I discovered just how bad the Delta is for LEO launch. It's so bad that Boeing doesn't even publish true launch curves for LEO in the the payload user's guide. I had to reconstruct them from published launch capacity to 185 km circ, estimated LEO launch mass, Is, and mass fraction.

I calculated the following numbers for payload to LEO(metric tons)*:

Rocket

payload to 500km(circ)

payload to 1000km (circ)

Atlas V 402

10.3t

9.1t

Atlas V 522

13.5t

12.0t

Atlas V 552

15.8t

14.0t

Delta IV 5,2

5.6t

5.1t

Delta IV 5,4

8.1t

7.2t

Delta IV Heavy

17.4t

16.2t

* these numbers included an inclination penalty to launch into a 64.3 degree orbit from the Cape, if anybody's looking at the actual payload curves.

Amazing, isn't it? the smallest Atlas V (402), with no solids on it, demolishes all but the Heavy, three core Delta IV. Which makes it all the more curious that the DOD still has contracts for Boeing to launch satellites to LEO with medium Deltas. WTF?

The Delta doesn't really gain any advantage until you start looking at higher altitudes. This is entirely due to the higher Isp RL-10B-2 (Isp 462s) vs. the RL-10A-4 (Isp 450s). It has nothing to do with the first stage.

Virtually any introductory course to rocketry will stress that higher ISP is 'better'. Most people liken it to miles per gallon in an automobile, an especially inapt comparison IMHO. By that measure, the first stage of the Delta IV, boasting the Isp 420s RS-68, should destroy the 'wasteful' Atlas V, w/ Isp 311s RD-180. The RD-180 has higher thrust to weight (70 for RD-180 vs 40 for RS-68) and overall thrust. But, of course, RP-1 weighs a lot more than LH2.

So what explains the discrepancy? The big problem as I understand it s that the Delta IV is thrust limited. In other words, the RS-68 has to limit its thrust while in the atmosphere to keep from structurally damaging the rocket itself. This has the effect of dramatically increasing the burn time of the first stage engine. As the Ambivalent Engineer makes clear in an excellent discussion on staging, more burn time for the first stage means higher gravity losses incurred for the same total impulse. So basically, Boeing developed this super-whamodyne LH2/LOX common core booster with a big honkin RS-68, for perceived higher efficiency, only to have to use it suboptimally because--oops, the first stage has to go through the atmosphere. It's a bit like dropping a high-torque truck engine into a small racecar, but forgetting that all that torgue goes to waste if the low-gear transmission and 10 inch wheels can't deal with it.

The Atlas V, on the other hand, with a much heavier mass at takeoff, is structurally stronger to begin with and runs at nearly its full thrust rating for the entire first stage burn. It incurs smaller gravity losses and the first stage is able to add a higher velocity increment as a result, which increases the payload on the second stage, despite having a lower 'efficiency' engine than the Delta IV.

Add to that the difficulty and expense of working with LH2, and the massive amounts of it you need on a lower stage, it makes one wonder--why use it on the CaLV lower stage at all?

Monday, May 08, 2006

Enough Already

One of my pet peeves about the blogosphere is the instant piling on that takes place whenever somebody makes a 'politically incorrect' statement in public.*I don't in any way condone* what Peter Diamandis said, and the very fact that I have to state that to keep from receiving angry links or comments is exactly what I'm talking about.There is a certain element in the blogosphere that takes extreme delight in calling attention to any and all slips of the tongue, inappropriate wording, and mistakes. It's a gotcha mentality that represents all the worst of reporting and the relative anonymity of being behind a keyboard.

NASAwatch does this all the time--a significant percentage of the postings are gotchas about this or that NASA release that doesn't exactly match up with an internal document, or two Griffen statements at different events that appear to contradict--more the point, often completely irrelevant to any major issue dealing with NASA.

The real joy, I guess, is in intimating that someone else has not done their homework or done their job right or some aspect of their job.

But personally, I'm just sick of the whole atmosphere. Our society should be secure enough that we don't have to go demanding self-flagellation whenever someone makes a slip of the tongue.

Accuracy in metaphors

Among the visionaries of the new frontier at the ISDC conference 2006, I'm sure it's tough to find naysayers about our (meaning humanity's) progress towards actually becoming a spacefaring civilization. Without a doubt, most of the speakers are preaching to the choir. I'm afraid that I mostly agree with Jeffrey Bell of UH (Hawaii). Jeff wrote this article a few years ago-- I read it at the time and agree with most of its major points. If you're going to use a historical analogy, better use it appropriately, and accept the positives AND negatives.

I saw it again tonight when I was trolling usenet--somebody reposted it. Probably the part of Bell's thesis that's most distressing to alt.space types is the contention that our technology level is currently too low. Here, I'll quote:

I think we are in the same position with respect to space flight that the Norsemen were in respect to colonizing Canada. Our chemical rockets are just as inadequate as the Viking longboats. Our spacesuits are as clumsy as chainmail armor. Our means of defense from solar and cosmic radiation are as ineffectiveas the Viking spears and axes were against the Indians. Our ideas for using local resources are as primitive as the farming and mining techniques of 1000 A.D.

Say that at ISDC, or worse, Space Access, and visionaries and alt.space geeks will fall all over themselves telling you that it's not true, that the technology exists today and just needs to be 'done right.'

I'd say that's a category I fell into until I got to school and started studying the actual physics and engineering required to get off-planet. TANSTAAFL is an excellent motto to keep in mind. Want higher performance engines? Be prepared to pay a hefty price. Reusable engines? Be prepared to pay a performance penalty. You have a completely new way of doing things? Be prepared for it to take 3 times as long, 4 times as much money, and 5 times as many failures as you initially budget for.

I do think there's one big hole in Bell's perspective of NASA as our society's version of Cheng Ho's journeys to nowhere: Cheng Ho's journeys may not have been able to challenge western technology, but as Bell himself stated, that was because Ming dynasty China could not compete with the real advances taking place in the West. The fact is, we ARE the West. The outward expansion begun in Prince Henry the navigator's day may be confined to our humble planet at the time, but the rational mind and the scientific method are alive and well. The cause of the technological advances that gave Western Europe the advantage over other cultures (for a time at least), is still currently in motion. Given enough time, we will develop more powerful engines, better ISRU techniques, and sufficient political will to really colonize space.The real question is whether our society will stick around that long or lapse into decline because of ever-falling birthrates.

Thursday, May 04, 2006

A rational solution to immigration

OK, I get tired of hearing the pundits of both sides argue about turning illegal immigrants into felons or about another amnesty that would encourage more law breaking.First, a disclaimer: although I am a legal native-born American, my grandfather, Thomas Long, illegally entered the US from Canada after immigrating there from Ireland. He worked on the docks in NY as a longshoreman for several years until he saved enough money to go back to Ireland, immigrate legally, and then fought in WWII shortly after receiving his legalization status. I don't condone my ancestor for working here illegally, but he desperately wanted to be a real American, so he rectified the situation as soon as he had sufficient means to do so.

I would submit that there are several truths that both sides can agree on:

There's no practical possibility of deporting 11 million illegals, if the number really is that high. It's just not possible. Every single one of those people pretty much gets a hearing. As if the federal courts aren't clogged enough as it is, dumping an extra 11 million cases on their hands is just not feasible, especially as they would be heavily concentrated in the border districts. That doesn't mention the likely effect this would have on the economy, as the cheap labor is suddenly taken off the market. That fact alone would make the INS's job even more unworkable than it already is, with politicians from both sides screaming about specific enforcement efforts killing their constituents.

Encouraging future lawbreaking is not desirable. However, there has to be some answer to the current rampant lawlessness with regard to immigration laws. Any solution has to take into account not only the specific cause of current lawbreaking but the concerns of a labor market producing more jobs than native-born Americans can fill.

So what is the cause of current law breaking? As this graph from a study done at Mizzou shows, the numbers of immigrants coming into the United States peaked around 1900 at close to 1 million/year, then dropped sharply, and has only recently come back to that level. But how many of those are legal? In 2003, only 463,000 people were made legal residents of the United States. Less than half the number of people immigrating(Legally!) in 1890. Keep in mind that the US population in 1890 was somewhere between 62-65 million. In other words, legal immigration was 2-3% of the total population per year. I think most Americans today would agree that that worked out pretty well in the long run. In contrast, in 2003, there were somewhere around 278 million Americans, and yet we only allowed short of 500,000 to join us in the greatest nation on Earth. That's 0.001% of our population. What the hell is wrong with us? Are we really that scared that 88 million Mexicans are going to overwhelm us 280 million Americans? Have math skills decayed that badly?

What, is the cause of the lack of assilimation that plagues many Mexican immigrants, especially in California? Conservatives like to blame the problem on liberal multi-culteral philosophy that is entrenched in our education system. Perhaps that plays a role. But I would argue that the main cause is the fact that so many of our immigrants are here illegally, never given the opportunity to raise their right hand and swear allegiance to this country and our consitution, is the main factor. When did our society lose the concept that words are important, even to those who barely understand what they are speaking? Keeping a noticeable percentage of the population restricted to the barrio, where they can hide safely in their illegal identity, is NOT a solution, and only perpetuates a 'seperate' identity. Granting amnesty to those already enmired in the current proto-slavery of illegal immigration would only perpetuate the current seperation in that population.

I would challenge conservatives who say that the problem is 'not immigrants, but "illegal" immigrants,' to put their money where their mouth is and start calling for drastically increased LEGAL immigration. I mean where the only requirement to immigrate and obtain a green card, beyond health issues, should be the ability to show up at a US port of entry and not be on a terrorist watch list.

This one stroke would solve a LOT of immigration problems. Illegals already in Amercia would find themselves competing against legals with the same hard work ethic, but much better prospects, raising immigrant wages. Many would be forced to go back to a port of entry and enter legally, or go home altogether. The very act of reentering the United States at a port of entry will act to break the 'barrio' mindset of many of these immigrants. Ceremonies and words have important effects on the human psyche.

Couple increased legal immigration with slightly stronger enforcement, especially on the payroll tax side, and suddenly the agricultural and meatpacking industries that rely so heavily on illegal labor, would have little reason to continue to do so.

There is no need to condone past illegal behavior, but there are ways to discourage future illegal behavior without throwing our economy under the Homeland Security bus.

Monday, April 17, 2006

Oooooh I won a free play on Space Shot!

I evidently got a free play by pointing out the 'finalizing . . .' bit. That's pretty neat.

Some other comments by Sam:

Our standings page is in development and should be ready by the time a player reaches the finals if not sooner.

We can only have the weather as specific as the National Weather Service Reports it. No sense in getting more granular when the NWS reports in whole degrees.

. . .

Right now, Space-Shot.com is the only way to win a trip to space for $3.50 as many as you want. No other way will have as broad a population that will be competitive in the skill.

I would definitely argue the granularity bit... Sam, you're thinking like a scientist, not a game player. If I say 50.20 and I am randomly matched up against someone who picked 50.25, I will win if the high is 50 or below. I'll lose if it's above 50 degrees.

It's not about scientific accuracy, it's about the ability to choose your proximity to the higher and lower numbers. It's about positioning.

Let me clear the air on Space-Shot.com

Just want to make it clear to anyone that finds their way to this post or the one below that on a personal level, I admire Sam Dinkin's efforts to get the rest of us to space. I admire his optimistic take on the challenges and rewards of getting spaceflight for the masses. That's one of the reasons his articles on The Space Review are usually one of my first reads of the week.

Starting up a new enterprise is an enormously challenging and backbreaking endeavor. Add in vagaries like domain squatters and eclectic interests of state Attorney Generals, and it can truly be a perilous and challenging journey.

All that said, my criticisms of the gameplay of Space Shot.com result from my experiences as a paying customer. In the end I can say whatever I want, but I'll put my money down to play again if I think it's worth the while of doing so. Right now I'm not there.

Trying out Space Shot

Okay, Lent's officially over, which means I get to post and surf the Internet whenever I choose.

I've been wanting to post on this topic, because it really is Space for everyone: Space-Shot.com. The overall idea by Sam Dinkin is great--the best part being that it's legally accessible from all states.

So far I've tried three plays. I won once and lost twice. Here's my overall impression:

1. Domain names matter. Twice early on I tried to get to the website by typing "www.spaceshot.com". Suprisingly, that takes you not to the official Space Shot website, but to a (perhaps different?) company with the message "space shot..this page under construction," with no pointers or links to the actual Space Shot website. I'm suprised that domain name wasn't also bought by Sam in an effort to ensure that everyone who tries to get to the correct website actually gets there. It'd be like Amazon.com not having the rights to 'amazon.com,' so they have to use 'amazon.net' instead.

2. 'Playing' it is actually not much fun. Especially when you can't try again till tomorrow. Sam Dinkin wanted to create a game where the chances of winning are the same for everyone, so that certain 'skill' players wouldn't dominate the competition and discourage beginners from trying. (See last week's article in The Space Review.) Great, that's part of the reason I was interested in trying it out. So I got the deal of 6 plays for $18 and sat down to try it out.

The first play, I picked a bunch of numbers pretty much close to the forecasted numbers. Within a few hours, I was matched up against 'Veomega.' We both picked numbers close to the forecasted highs,lows, humidities, and precipitation. I was 1/2 a degree lower than forecasted, he was 1/2 a degree higher.

Here's a confusing bit: When you pick your plays, and finalize predictions, the site says "Finalizing predictions ...", but then never lets you know that it's done. It looks like it locked up on 'Finalizing...', although if you go back to the front page, it shows the picks as actually finalized.

Then we waited...and waited.. In effect, it was a 3 day play. We picked our plays on the 8th, sat through the 9th while the weather data was collected, and couldn't actually check it out till the 10th. I certainly wasn't going to try again until I knew how the first one went.As for the results..frustrating. Both of us were way off, the actual temperature was nearly 20 degrees higher than forecasted. Nevertheless, since I was lower than 'Veomega', he advanced and I lost.

The next time I tried it I tried a double combo 'higher' and 'lower'. I picked numbers as close to the forecasted as possible, with one higher, and the other lower, than the forecasted values. Unsuprisingly, I lost one and won the other.

So I did three plays in a week, one advancing and two losing. And to be honest, I have no real interest in continuing. Oh, I will play out my remaining hands. But I won't be paying any more money unless some changes are made.

In fact, here's the big problem--it is actually a game of chance when you get down to it, which would argue for a fast, casino style of play. But each play takes DAYS. There's no hurrying it. So, any excitement from a win is gone by the time the next play comes. There's no hope of getting a win to salvage your pride following a disappointing loss until the next play is over--that's two days from now!

3. No Standings: This is a big mistake in my book. Part of the reason I have no interest in continuing is because I have no idea where my two losses and one wins place me. How many people are at level two? how far would I have to go before I have trouble getting a match? How close are we all total to getting someone to orbit? How many would I have to win to get my name in the neon lights? Status is an important motivator. This is stuff that should be on the front page.There's a reason most bloggers check their TTLB ecosystem standings every day. People want to know just where they stand.

4. Top frustration with single hand gameplay: In order to reduce ties, the highs and low temperatures are forced into a 'x.25 degrees', 'x.75 degrees'. But you can play out number of inches of rainfall to the hundreth of an inch. Remember, the order of competition is highest temp-->lowest temp-->rainfall-->humidity. So you have less granularity in your initial pick to tie than you do in your tiebreaker. What kind of crap is that?

As it currently is, it feels like the pace of playing the stock market, but you lose your investment entirely if you don't gain, instead of just losing a percentage of it. So here are my top three suggested improvements for Space Shot:

1. get standings on the front page, as a minimum with the levels and names of top players, along with the numbers of players at each level.

2. get the domain name for www.spaceshot.com and point it to the homepage, so everybody gets there on their first try.

3. fix the 'finalizing predictions' to update when it's done so that first-time users don't think it locked up.

Here's a suggestion for the long term, if this is intended to continue beyond the initial interest phase: allow some type of game to be played that allows instant matching and feedback. This is not a simple fix, and would radically change the way space shot is structured. But as it is now, there's no real fun to playing Space Shot. The only 'fun' comes from knowing you're closer to winning that prize to space. But that's not real fun. I get closer to buying my own trip to space for every dollar I earn too. Which means Space Shot is more like work than fun--the difference being it costs you money.

For example, one way that might be fun is a 'skill' game involving an element of luck--like an online version of 'Lemonade Stand','Monopoly,' or 'Risk'. The chance could be reduced below the threshold at which it becomes a game of chance, with the advantage that feedback would be instantaneous. Losing that way is actually kind of fun.

Anyway, I think there's ways to do this better that would be more fun. The lure of eventual spaceflight, however, is far too distant with Space Shot as it currently plays.

comments stuff

Friday, April 07, 2006

attacking ATK --Updated 4/10/06

The usual suspects of Big Aerospace tomfoolery, Boeing and Lockheed, appear to have been shut out of the CEV launch market. The sole source provider, ATK, is therefore in the unusual position (for ATK as compared to BLoMart)of bearing the brunt of angry alt.spacer's tinfoil hattery.

Rand first complains about the sell:

Nice bait and switch--you have to admire ATK for their marketing, if nothing else.

Okay, that's reasonable. But then he implys EELVs could have done the job if it wasn't for human rating:

And tell me again, what was the estimate to "human rate" an EELV? And more to the point, how many very juicy first, second and third prizes for low-cost crew access to LEO could three billion dollars fund?

I won't even touch the rather laughable politics of basing a federal multi-billion dollar program on the possible success of a prize-award system.

But as for human rating an ELV, is that true?

Griffen pretty clearly stated last year that if the next manned launcher was going to pass muster, it could not have multiple cores or a side-mounted crew compartment because of the increased complexity and numerous failure modes that impact surviveablity. When I get some time I'll find the studies that backed that up.

That constraint limits EELV's options to the Delta-IV and Atlas-V single core, medium versions.Max payload for medium Delta IV, 10.3 metric ton(t) and for Atlas-V 17 t. If you follow the (usual alt.space) mantra that solids are deadly --especially the ones that have explosively destroyed a mountain like Delta's--cut that medium to a no-solids medium. Now you're at 7 t for Delta and 12 t for Atlas.

That might be enough for a CEV designed by George W. Herbert, but NASA has evidently decided it needs much...much...much more, so it would seem man rating the EELV is not the issue here--it's uprating and manrating.

As for the tin hat part:

Also, for any enterprising muckraising space journalists out there, this has been a juicy scandal waiting to happen, what with Scott Horowitz' recent job change, and all. Moreover, it could potentially be one that kills the Satay (or as Henry Spencer calls it, Porklauncher I).

okay, now we're implying a Darleen Dryun size contractor steering scandal--maybe an inflation of costs to improve ATK profit. At first glance, seems plausible. After all, Scott Horowitz moved directly from developing the plan at NASA to selling the plan at ATK to managing the Exploration systems that will buy the ATK booster. Fishy fishy fishy, right?

Here's the reality of that--unlike with Boeing's scandal, there is no existing system that could fulfill NASA's requirements for cheaper. (Darleen Dryun was getting the Pentagon to overpay for renting KC-737s when it would have been cheaper to buy them outright.) In fact, there's no existing system that can fulfill NASAA's requirements anyway, which is why ATK is going to be awarded a single-source contract to help with the new launcher booster with little fuss.

As for the Horowitz connection, Scott Horowitz developed the CLV plan at the JSC spaceflight office when it became apparent that OSP was not going to go anywhere(2001 timeframe), but O'Keefe refused to make any movement on a new launcher, which is why Horowitz left for ATK(in 2004). Griffin then brought Horowitz back to NASA after he became the new administrator (late 2005). In other words, Horowitz got the ATK job offer after O'Keefe had declined to pursue the idea(in 2001). It was Griffin who brought Horowitz back.That's not steering government contracts to a specific contractor to the disadvantage of the government(as with Boeing). That's getting the contractor on board with governmental intentions.

Second of all, as I said in the comments on Rand's site,the original estimate for the CEV mods was assuming 2 things 1. a 4 segment SRB w/ one J2S or J2X and 2. a lighter CEV.

When ESMD said the CEV had to be nearly 20 t, that mandated a 2-J2 or 1-SSME soln instead; the airstart SSME, while reasonable at first glance, was on the whole a dead-end, which is why it was dropped in favor of the more architecture-friendly J2X.

So it would seem the root cause of the problem here is the excessive weight of the CEV, not a Darleen Dryun style conflict of interest.